1574-1660

English Mathematician

An Anglican priest who tutored students in mathematics, William Oughtred invented both the linear and the circular slide rules. He also introduced the symbol x for multiplication, and :: for proportion.

Oughtred was born in Eton on March 5, 1574. His father, Benjamin, taught writing at Eton School, which Oughtred attended as a king's scholar. At age 15, he entered King's College at Cambridge, where he earned his B.A. degree seven years later, as well as an M.A. in 1600. Though mathematics was not his area of study, it was during this time that Oughtred developed a keen interest in the subject such that even after he was ordained as a priest, he tutored math students without receiving any pay. His salary as a clergyman, he said, was sufficient to cover his needs.

Following his ordination in 1603, Oughtred received an assignment to serve as vicar of...